Machines for securing a metal strap around a container, box, package or the like



April 23, 1963 A. VAN DER WA MACHINES FOR SECURING A METAL STRAP AROUND A CONTAINER, BOX, PACKAGE OR THE LIKE Filed July 18. 1960 3 Sheets-Sheet l INVENTOR Au e Van Dex WU M1xua.\\ E. gvaxvaw ATTORNEY April 23, 1963 A. VAN DER WAL MACHINES FOR SECURING A METAL STRAP AROUND A CONTAINER, BOX, PACKAGE OR THE LIKE Filed July 18, 1.960

5 Shets-Sheet 2 INVENTOR Auka Van Dev EA M we E, E apvow ATTORNEY April 23, 1963 A. VAN DER WAL 3,0 ,4

MACHINES FOR SECURING A METAL STRAP AROUND A CONTAINER, BOX, PACKAGE OR THE LIKE Filed July 18, 1960 5 Sheets-Sheet 3 INVENTOR Mlxwe E. Sgrawvow ATTORNEY United States Patent 0.

MACHINES FOR SECURING A METAL STRAP AROUND A CONTAINER, BOX, PACKAGE OR THE LIKE Auke van der Wal, The Hague, Netherlands, assignor to N-V. Verenigde Metaalverpaklring Maatsch'appij, The Hague, Netherlands, a company of the Netherlands Filed July 18, 1960, Ser. No. 43,505 Claims priority, application Netherlands Oct. 1, 1959 2 Claims. (Cl. 100-46) The invention relates to a machine for securing a metal strap around a container, box, package or the like and the invention has for its object to provide a machine for this purpose such that the strap is tightly tensioned around the box or container and the tensioning force can if necessary be so increased that the strap is broken off after the fixing operation.

In accordance with the invention, the strap is guided between two meshing toothed gear wheels, one of which is adjustable, towards and away from the other and the teeth of at least one of the gear wheels are made of smaller height for a part of the tooth length over the width of the strap and one Wheel is connected by a slipping -clutch to a driving shaft. Thus, if the gear wheels are moved towards one another the strap can be tensioned more or less tightly around the container or box until the said connection between the gear wheel and the driving shaft slips. Advantageously, one of the gear Wheels is mounted on a lever which also carries one of a pair of rollers between which the strap is fed and the arrangement is so designed that with the movement of the lever for moving the gear wheels towards one another, one roller is moved away from the other roller, so that the rollers are no longer effective for feeding the strap.

It is furthermore advisable for this arrangement to be so constructed that the driving shaft of the driven gear wheel can be coupled to the latter through a delay gearing so that the strap, after being secured around the container or box, can be broken off by the rotation of the gear wheel.

It has been found that the clamping of the strap between teeth of the gear wheels causes the formation of weak zones in the strap, so that when the tension of the strap is increased after completing the fastening operation, the strap is not broken off at the fastening position but at another position. In order that this disadvantage may be avoided, the effective flanks of the tooth crests on the reduced portions of the teeth on at least one of the gear wheels are preferably each formed with a recess. This prevents the strap from being clamped so strongly at the tooth crests between the teeth of the two gear wheels so that no indentations are formed in the strap and the latter is thereby not damaged. The gear wheels are pro? vided with three axially spaced sets of teeth.

The invention will be more fully explained by reference to the drawings, wherein:

FIG. 1 is a front elevation, partly in vertical section, showing one embodiment of the machine according to the invention.

FIG. 2 is a view to a larger scale showing the machine drive as indicated in FIG. 1.

FIG. 3 is a sectional view of said drive means along the line III-III of FIG. 2.

FIG. 4 is a view to a larger scale, partly in side elevation and partly in section (the front set of teeth being omitted so that the middle set and a portion of the back set can be viewed), showing portions of two gear wheels with teeth of a different form.

FIG. 5 is an axial section on the line V-V of FIG- URE 4.

FIG. 6 is a perspective view of one of the strap clamping gears.

3,086,451 Patented Apr. 23, 1963 "ice The frame 1 of the machine has an upper plate 2, on which are arranged a guide member 3 and another guide member 4 for the metal strap 5, which is unwound from a reel 6. The strap also runs over a guide roller 7 and between two feed rollers 8 and 9, the roller 8 being fixed on a shaft 10 and the roller 9 being rotatably mounted on a lever 11, which has a fixed fulcrum 11a.

Engaging the lever 11 is a rod .12 carrying an armature 13 which co-operates with two electro-magnets, 14, 15 arranged one above the other.

The lever 11 also has a gear wheel 16 mounted to ro tate freely thereon, the said wheel co-operating with a corresponding gear wheel 17, the strap 5 being guided between these two wheels 16, 17. The teeth of the two wheels 16, 17 mesh with one another, but the middle set of teeth are made recessed over the major part of their axial length, so that the strap can pass freely even when the gear wheels are inter-meshing, as will be seen from FIG. 3. The feed rollers 8, 9 and the gear wheels 16, 17 serving to tension the strap are driven by a driving shaft 18, but the gear wheel 17 is arranged so as to be freely rotatable on its shaft 18 and can be driven by a friction disc 19 as the shaft rotates, the said disc being connected fast to a gear wheel 29 fixed on the shaft.

Arranged adjacent the shaft 18 is an auxiliary shaft 2-1 on which is fixed a gear Wheel 22 meshing with the wheel 20 on the shaft 18. The shaft 21 also has a gear wheel 23 mounted for free rotation thereon and this wheel 23 is combined with a coupling disc 24 which can be coupled with the gear wheel 22 by displacement along the shaft. Combined with the gear wheel 17 for tensioning the strap is a gear wheel 25 which meshes with the gear Wheel 23 of the shaft 21 and consequently can also be rotated freely about the shaft 18.

The strap 5 co-operates with a feeler member 26 and the shaft 27 of this feeler member carries an arm 28 for engaging a projection 29 on a coupling disc 30 for locking said disc. Coupling disc 30 is combined with a cam disc 31 and this combination is mounted so as to be freely rotatable on a shaft 10' on which a gear wheel 33 is secured. The gear Wheel 33 meshes in a gear wheel 34 arranged on the shaft 18.

The arrangement indicated above simply by way of example operates as follows. When a strap is to be secured around a box k, a press button 35 is pressed, whereby current flows through a contact 36 and a feeler member 37 and through the coil of the magnet 14 and the armature 13' is pulled downwardly carrying the lever 11 with it, so that the latter pivots about the shaft 11a and the strap is forced by the roller 9 against the rotating roller 8 and is laid in a loop in the guideway of the caps 3, 4. The end of the strap will then force the feeler member 37 downwardly and thereby open the contact 36, so that the press putton 35 springs back, the magnet 14 is without current and the lever 11 returns under the action of the springs 3-8 to its original position.

If new the strap has to be tensioned around the box k, the press button 39 is depressed, whereby current flows through a switch 40 and through the coil of the magnet 15, the armature 13 is moved upwardly and the lever is also moved upwardly by the rod 12. The lever 11 then reaches the position 11' shown in FIG. 2. This movement of the lever is limited by a cam 41 on the disc 31 and, by this movement of the lever 11, the roller 9 is freed from the roller 8, so that the strap cannot be fed any further. The strap is then retracted, since the gear wheel 16 is moved towards the gear wheel 17 and thereby the strap is clamped. Upon tensioning of the strap, the feeler arm 26 in FIG. 2 is forced towards the right by the tightened strap, so that it reaches the position shown in dotted lines and thereby the arm 28 disengages the projection 29 on the coupling disc 30, so that said disc can now be rotated by the gear wheel 33 and consequently the cam disc 31 is also rotated. The cam 41 is now freed from the lever 11, so that the latter can move into the position 11" shown in FIGURE 2. By this movement of the lever 11, the gear wheels 16, 17 mesh more deeply one within the other, so that they draw the strap tight until the gear wheel 17 starts to slip on the disc 19.

The fastening of the strap is effected by means of the cam disc 31, which is provided with a projection 47 actuating the fastening mechanism 42 by means of linkage 48. This fastening is advantageously effected by lips being cut out at one end of the strap, these lips being bent over through cutouts on the other end of the strap. It has been found that with the increase in the tension in the strap, the latter is broken off at the position of the fastening cut-out. In order to effect this breaking-off operation after the ends of the straps have been connected to one another, the cam disc 31 controls the coupling 24, for example mechanically, whereby the gear wheel 23 is coupled to the gear wheel 22, so that now the gear wheel 20 drives the gear wheel 17 through the coupling disc 24 and the tensile force in the strap is so increased that the strap is broken off immediately behind the securing position.

In order to bring the mechanism back to its starting position the cam disc 31 is provided with a cam 43 acting on the switch 40, so that the electric circuit is broken, the button 39 springs back and, by means of the cam disc 31, the connection between the coupling disc 24 and the gear wheel 22, and also the connection between the coupling 30 and the gear wheel 33 is broken. The lever 11 then also reaches its original position again under the action of the springs 38.

In the constructional form according to FIGS. 4, and 6, the gear wheel 17 which is connected with the driving shaft 18 by a slipping clutch, and also the freely rotatable gear wheel 16, are each provided with three axially spaced sets of teeth 44, 45. Both outer sets of teeth 45 of gears 16, 17 have their normal height, but the teeth 44 of the middle set, extending over the major part of the axial length of the gears 16, 17, are recessed at their heads and therefore are of reduced height. Each one of the teeth 44 of the middle set of the teeth of the gears 16, 17 is of this length. The teeth 44 of the gear wheel 16 are each provided at the effective flanks with a recess 46 so that the sharp edge at the crest of the recessed portion of each of these teeth is free from the teeth of the gear wheel 17 and this sharp edge can no longer clamp and indent the strap. I

What I claim is:

1. A machine for fastening a metal strap around a box or the like, comprising in combination strap feeding means, means for guiding said strap around said box, strap tensioning means and strap fastening means, said tensioning means being provided with two toothed and intermeshing wheels between which the strap is guided, each of said toothed Wheels having three sets of teeth at its circumference and having the teeth of the middle set of said teeth of at least one of said wheels recessed at the head thereof extending over an axial length corresponding to at least half the width of said wheel, said recessed teeth being further recessed at their effective flanks for accommodating said strap between said flanks of said intermeshing teeth, driving means for one of said toothed wheels and a slipping coupling in said driving means.

2. A machine for fastening a metal strap around a box or the like, comprising in combination strap feeding means, means for guiding said strap around said box, strap tensioning means and strap fastening means, said tensioning means being provided with two toothed and intermeshing wheels between which the strap is guided, each of said toothed wheels having three sets of teeth at its circumference and having the teeth of the middle set of said teeth of at least one of said wheels recessed at the head thereof over an axial length corresponding to at least half the width of said Wheel, said recessed teeth being further recessed at their effective flanks for accommodating said strap between said flanks of said intermeshing teeth, driving means for one of said toothed wheels, a slipping coupling and a retarding gearing in said driving means for transmitting suflicient torque to said toothed wheel to break off said strap after being fastened around said box.

References Cited in the file of this patent UNITED STATES PATENTS 2,195,043 Wright Mar. 26, 1940 2,438,386 Chamberlain Mar. 23, 1948 2,701,936 Drummond Feb. 15, 1955 2,914,643 Fields et al Nov. 24, 1959 2,915,004 Leslie Dec. 1, 1959 

1. A MACHINE FOR FASTENING A METAL STRAP AROUND A BOX OR THE LIKE, COMPRISING IN COMBINATION STRAP FEEDING MEANS, MEANS FOR GUIDING SAID STRAP AROUND SAID BOX, STRAP TENSIONING MEANS AND STRAP FASTENING MEANS, SAID TENSIONING MEANS BEING PROVIDED WITH TWO TOOTHED AND INTERMESHING WHEELS BETWEEN WHICH THE STRAP IS GUIDED, EACH OF SAID TOOTHED WHEELS HAVING THREE SETS OF TEETH AT ITS CIRCUMFERENCE AND HAVING THE TEETH OF THE MIDDLE SET OF SAID TEETH OF AT LEAST ONE OF SAID WHEELS RECESSED AT THE HEAD THEREOF EXTENDING OVER AN AXIAL LENGTH CORRESPONDING TO AT LEAST HALF THE WIDTH OF SAID WHEEL, SAID RECESSED TEETH BEING FURTHER RECESSED AT THEIR EFFECTIVE FLANKS FOR ACCOMMODATING SAID STRAP BETWEEN SAID FLANKS OF SAID INTER- 